Arterial spin labelling: predictive role in surgical bleeding of paediatric optic pathway gliomas.

To analyse the performance of arterial spin labelling (ASL) in predicting surgical bleeding in a paediatric cohort of optic pathway glioma (OPG). Preoperative ASL data were obtained for 51 OPG in 40 patients, aged from 9 months to 16 years. The relative cerebral blood flow (rCBF) in the tumour areas with the highest CBF (maximum rCBF) was measured and then correlated with qualitative local bleeding (graded no, moderate, and major by the neurosurgeon) and quantitative global surgical bleeding (assessed in millilitres using haematocrit data). Intratumoural maximum rCBF was significantly higher when qualitative local bleeding was high (median value in the no, moderate, and major bleeding groups equal to 0.81, 1.39 and 4.22, respectively, p= 0.004), but there was no difference in global quantitative bleeding (p= 0.7 for the total blood loss). The maximum tumour rCBF cut-off value of 1.1 yielded a sensitivity of 73%, a specificity of 78%, and an accuracy of 76% (39/51 tumours) in detecting haemorrhagic OPG. Choosing a maximum tumour rCBF cut-off value > 1.7 improved the specificity in diagnosing tumours with high bleeding risk with a specificity of 94%, a sensitivity of 53%, and an accuracy of 82% (42/51 tumours). ASL tumoural rCBF is a useful and simple diagnostic tool to help predict high intraoperative tumoural bleeding risk in paediatric OPG. • Tumor cerebral blood flow helps to predict qualitative surgical bleeding. • Relative tumor blood flow greater than 1.1 is associated with hemorrhagic glioma. • Larger resected area is associated with higher quantitative hemorrhage. [ABSTRACT FROM AUTHOR]